The invention concerns toilet paper. Toilet paper is usually manufactured as rolls; for some uses it may be precut into sheets of suitable sizes.
Standard types of toilet paper are made of crepe paper or tissue paper arranged in one or more plies. An essential criterion for the quality of the paper is its resistance to tearing when wet, its so-called "wet strength". The toilet paper ordinarily available has inadequate wet strength. The consequences thereof are immediately obvious and require no elaboration.
In order to compensate for this shortcoming, the user must fold several sheets over one another. A means of avoiding this need would be increasing the number of plies in the paper during manufacture. Both of these practices are undesirable due to their inefficient use of paper.
It is known from German utility model No. 19 39 788 to add an additional paper ply onto a paper strip along the longitudinal axis of said paper strip, or to insert an additional narrow paper strip between two plies having normal width. Unfortunately the manufacture of this kind of toilet paper has shown to be rather difficult.